1. Field of the Invention
This invention relates to a method of preparing a boric acid modified aminoamide compound and a lubricating oil composition containing the same.
2. Prior Art
Aminoamide compounds have been found useful as a dispersant for engine oil, particularly two stroke cycle engine oil. It is well known that about 9-20 weight percent of aminoamide dispersants are formulated in an engine oil typically conforming to outboard two stroke cycle engine oil specification, namely, NMMA TC-W or TC-WII. However, due to their lack of thermal stability, the conventional aminoamide dispersants were often found incapable of detergency performance and preventing piston ring sticking when exposed to elevated temperature in an outboard high-output engine or an air-cooled two stroke cycle motorcycle engine. A growing demand has therefore arisen for such aminoamide dispersants which retain their intrinsic low-temperature detergency performance and yet demonstrate enhanced detergency capabilities at high temperature.
It is also known to modify dispersants such as succinimide by modifying with boric acid thereby improving high-temperature performance, but with no significant results. No reports however have heretofore been made on the treatment of aminoamide dispersants with boric acid.